1. Field of the Invention
The invention relates generally to wireless communications and more particularly to call processing in wireless communications.
2. Background
Consumers are increasingly demanding push to talk (PTT) functionality on wireless communication devices. Dedicated PTT wireless communication infrastructure is expensive. Consumers want an inexpensive PTT solution. A way to perform PTT calls over a voice network is needed.
Changing network infrastructure is expensive, even if the change is only a software change. It would be preferable, if possible, to implement PTT over a voice network without modifying the network very much, if at all.
A problem with PTT calls over a voice channel is that the wireless communication device may react as if a standard voice call has been received in response to the PTT call. This may result in several possible problems. First, the wireless communication device may ring. The wireless communication device is not supposed to ring in a PTT call. Second, the wireless communication device may not be able to “take the floor” in the PTT session. “Taking the floor” means making one's wireless communication device the sender, such as, for example, the speaker, while one has “the floor”. Typically, only one PTT device in a PTT session (call) can be the sender at a time.
Moreover, delay in setting up a PTT session is another problem. Users want to be able to speak to the recipient of a PTT call as quickly as possible after they initiate the call. For some users, delay in call set-up time amounts to wasted time on the job. Alternatively, for some users, delay in call set-up time amounts to wasted time when they want to communication with someone personally.